U.S. patent application number 14/476241 was filed with the patent office on 2015-03-05 for semiconductor arrangement, method for producing a semiconductor module, method for producing a semiconductor arrangement and method for operating a semiconductor arrangement.
The applicant listed for this patent is Infineon Technologies AG. Invention is credited to Gottfried Beer, Irmgard Escher-Poeppel, Juergen Hoegerl, Olaf Hohlfeld, Peter Kanschat.
Application Number | 20150061144 14/476241 |
Document ID | / |
Family ID | 52470487 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150061144 |
Kind Code |
A1 |
Beer; Gottfried ; et
al. |
March 5, 2015 |
Semiconductor Arrangement, Method for Producing a Semiconductor
Module, Method for Producing a Semiconductor Arrangement and Method
for Operating a Semiconductor Arrangement
Abstract
A semiconductor arrangement includes upper and lower contact
plates and basic chip assemblies. Each chip assembly has a
semiconductor chip having a semiconductor body with upper and lower
spaced apart sides. An individual upper main electrode and an
individual control electrode are arranged on the upper side. The
chip assemblies have either respectively a separate lower main
electrode arranged on the lower side of the semiconductor chip of
the corresponding basic chip assembly, or a common lower main
electrode, which for each of the chip assemblies is arranged on the
lower side of the semiconductor body of that chip assembly. An
electrical current between the individual upper main electrode and
the individual or common lower main electrode is controllable by
its control electrode. The chip assemblies are connected to one
another with a material bonded connection by a dielectric embedding
compound, forming a solid assembly.
Inventors: |
Beer; Gottfried;
(Nittendorf, DE) ; Escher-Poeppel; Irmgard;
(Duggendorf, DE) ; Hoegerl; Juergen; (Regensburg,
DE) ; Hohlfeld; Olaf; (Warstein, DE) ;
Kanschat; Peter; (Soest, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Infineon Technologies AG |
Neubiberg |
|
DE |
|
|
Family ID: |
52470487 |
Appl. No.: |
14/476241 |
Filed: |
September 3, 2014 |
Current U.S.
Class: |
257/773 ;
438/107 |
Current CPC
Class: |
H01L 24/97 20130101;
H01L 2224/24195 20130101; H01L 21/568 20130101; H01L 2924/12042
20130101; H01L 23/5226 20130101; H01L 2924/19043 20130101; H01L
2924/13055 20130101; H01L 25/50 20130101; H01L 24/33 20130101; H01L
23/051 20130101; H01L 2924/1305 20130101; H01L 23/3107 20130101;
H01L 2224/03002 20130101; H01L 2224/82039 20130101; H01L 2924/13055
20130101; H01L 2924/19041 20130101; H01L 23/562 20130101; H01L
24/90 20130101; H01L 2924/13091 20130101; H01L 21/566 20130101;
H01L 2924/1301 20130101; H01L 23/528 20130101; H01L 24/72 20130101;
H01L 24/96 20130101; H01L 24/24 20130101; H01L 2924/1305 20130101;
H01L 25/072 20130101; H01L 2224/96 20130101; H01L 2224/33181
20130101; H01L 2924/19105 20130101; H01L 2924/1301 20130101; H01L
21/56 20130101; H01L 2224/06181 20130101; H01L 2224/24137 20130101;
H01L 2224/29011 20130101; H01L 2924/35 20130101; H01L 21/561
20130101; H01L 2924/13091 20130101; H01L 24/82 20130101; H01L
2924/00 20130101; H01L 2924/00 20130101; H01L 2924/19042 20130101;
H01L 2924/00 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
257/773 ;
438/107 |
International
Class: |
H01L 23/00 20060101
H01L023/00; H01L 23/522 20060101 H01L023/522; H01L 23/528 20060101
H01L023/528; H01L 25/07 20060101 H01L025/07; H01L 25/00 20060101
H01L025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 5, 2013 |
DE |
10 2013 217 802.6 |
Claims
1. A semiconductor arrangement, comprising: an upper contact plate
and a lower contact plate; a number of basic chip assemblies, each
of which has: a semiconductor chip having a semiconductor body, the
semiconductor body having an upper side and a lower side opposite
the upper side, and the upper side being separated from the lower
side in a vertical direction; an individual upper main electrode
arranged on the upper side; and an individual control electrode
arranged on the upper side; wherein the basic chip assemblies have
either respectively a separate lower main electrode, which is
arranged on the lower side of the semiconductor chip of the
relevant basic chip assembly, or a common lower main electrode,
which for each of the basic chip assemblies is arranged on the
lower side of the semiconductor body of that basic chip assembly;
wherein, for each of the basic chip assemblies, an electrical
current between the individual upper main electrode and the
individual or common lower main electrode is controllable by means
of its control electrode; a dielectric embedding compound, by which
the basic chip assemblies are connected to one another with a
material bonded connection so as to form a solid assembly; a
control electrode interconnection structure, which is embedded in
the solid assembly and which electrically conductively connects the
control electrodes of the basic chip assemblies to one another.
2. The semiconductor arrangement of claim 1, wherein: (a) each of
the basic chip assemblies has an electrically conductive upper
compensating die, which is arranged on the side of the upper main
electrode facing away from the semiconductor body and which is
connected with a material bonded connection and electrically
conductively connected by means of an upper connecting layer to the
upper main electrode; or (b) the basic chip assemblies have a
common electrically conductive upper compensating plate, which for
each of the basic chip assemblies is arranged on the side of the
upper main electrode facing away from the semiconductor body and
which is connected with a material bonded connection and
electrically conductively connected by means of an upper connecting
layer to the upper main electrode.
3. The semiconductor arrangement of claim 2, wherein the upper
connecting layer is formed as a solder layer or as an adhesive
layer, or as a layer of a sintered metal powder.
4. The semiconductor arrangement of claim 2, wherein: in case (a)
the upper compensating dies respectively have a linear thermal
expansion coefficient of less than 11 ppm/K; or in case (b) the
upper compensating plate has a linear thermal expansion coefficient
of less than 11 ppm/K.
5. The semiconductor arrangement of claim 2, wherein: in case (a)
the upper compensating dies respectively have a thickness of at
least 0.4 mm in the vertical direction; or in case (b) the upper
compensating plate has a thickness of at least 0.4 mm in the
vertical direction.
6. The semiconductor arrangement of claim 2, wherein the upper
contact plate has a plane surface section on its side facing toward
the lower contact plate, which: in case (a) electrically contacts
the side, of the upper compensating die of each of the basic chip
assemblies, facing away from the semiconductor body; or in case (b)
electrically contacts the side of the upper compensating plate
facing away from the semiconductor body.
7. The semiconductor arrangement of claim 2, wherein the upper
contact plate, on its side facing toward the lower contact plate:
in case has an upper contact elevation for each of the basic chip
assemblies, which electrically contacts the side, of the upper
compensating die of each of the basic chip assemblies, facing away
from the semiconductor body; or in case (b), has an upper contact
elevation for each of the basic chip assemblies, which electrically
contacts the side of the upper compensating plate facing away from
the semiconductor body.
8. The semiconductor arrangement of claim 1, wherein: (c) each of
the basic chip assemblies has an electrically conductive lower
compensating die, which is arranged on the side of the lower main
electrode facing away from the semiconductor body and is connected
with a material bonded connection and electrically conductively by
means of a lower connecting layer to the lower main electrode; or
(d) the basic chip assemblies have a common electrically conductive
lower compensating plate, which for each of the basic chip
assemblies is arranged on the side of the lower main electrode
facing away from the semiconductor body and is connected with a
material bonded connection and electrically conductively by means
of a lower connecting layer to the lower main electrode.
9. The semiconductor arrangement of claim 8, wherein the lower
connecting layer is formed as a solder layer or as an adhesive
layer, or as a layer of a sintered metal powder.
10. The semiconductor arrangement of claim 8, wherein: in case (c)
the lower compensating dies respectively have a linear thermal
expansion coefficient of less than 11 ppm/K; or in case (d) the
lower compensating plate has a linear thermal expansion coefficient
of less than 11 ppm/K.
11. The semiconductor arrangement of claim 8, wherein: in case (c)
the lower compensating dies respectively have a thickness of at
least 0.4 mm in the vertical direction; or in case (d) the lower
compensating plate has a thickness of at least 0.4 mm in the
vertical direction.
12. The semiconductor arrangement of claim 8, wherein the lower
contact plate has a plane surface section on its side facing toward
the upper contact plate, which: in case (c) electrically contacts
the side, of the lower compensating die of each of the basic chip
assemblies, facing away from the semiconductor body; or in case (d)
electrically contacts the side of the lower compensating plate
facing away from the semiconductor body.
13. The semiconductor arrangement of claim 8, wherein the lower
contact plate, on its side facing toward the upper contact plate:
in case (c) has a lower contact elevation for each of the basic
chip assemblies, which electrically contacts the side, of the lower
compensating die of each of the basic chip assemblies, facing away
from the semiconductor body; or in case (d) has a lower contact
elevation for each of the basic chip assemblies, which electrically
contacts the side of the lower compensating plate facing away from
the semiconductor body.
14. The semiconductor arrangement of claim 1, further comprising a
dielectric spacer ring arranged between the upper contact plate and
the lower contact plate and surrounding the basic chip
assemblies.
15. The semiconductor arrangement of claim 1, further comprising an
electrically conductive connection piece, which: is embedded in the
embedding compound; is electrically conductively connected to the
control electrodes by the control electrode interconnection
structure; is electrically contacted by a connection electrode
which is passed through a feed-through formed in the embedding
compound.
16. The semiconductor arrangement of claim 15, wherein the
feed-through extends starting from a side edge of the solid
assembly in a direction perpendicular to the vertical direction
into the embedding compound, as far as the connection piece.
17. The semiconductor arrangement of claim 1, wherein the control
electrode interconnection structure is formed as a printed circuit
board, or as a structured metallization layer.
18. The semiconductor arrangement of claim 1, wherein the
semiconductor body has a spacing of at least 300 .mu.m to the
immediately adjacent basic chip assemblies.
19. The semiconductor arrangement of claim 1, wherein the control
electrode interconnection structure has a conformally deposited
conductor structure.
20. The semiconductor arrangement of claim 19, wherein the
conformally deposited conductor structure has a thickness in the
range of from 30 .mu.m to 70 .mu.m.
21. The semiconductor arrangement of claim 1, wherein the control
electrode interconnection structure contains at least one passive
component, which is embedded in the embedding compound and which:
is arranged on a conductor structure of the control electrode
interconnection structure; and/or is a constituent part of the
conductor structure of the control electrode interconnection
structure.
22. A method for producing a semiconductor module, the method
comprising: providing a carrier; providing a dielectric embedding
compound; providing a number of basic chip assemblies, each of
which has: a semiconductor chip having a semiconductor body, the
semiconductor body having an upper side and a lower side opposite
the upper side, and the upper side being separated from the lower
side in a vertical direction; an individual upper main electrode
arranged on the upper side; and an individual control electrode
arranged on the upper side; arranging the basic chip assemblies
next to one another on the carrier; electrically connecting the
control electrodes by means of a control electrode interconnection
structure; embedding the basic chip assemblies arranged on the
carrier and the control electrode interconnection structure
electrically connecting the control electrodes into the embedding
compound; and subsequently curing the embedding compound so that
the basic chip assemblies with one another, and the control
electrode interconnection structure with the basic chip assemblies,
are firmly connected to one another by the embedding compound and
the basic chip assemblies together with the control electrode
interconnection structure and the embedding compound form a solid
assembly, wherein either each of the basic chip assemblies has an
individual lower main electrode, which is arranged on the lower
side of the semiconductor body of the corresponding basic chip
assembly, or a lower main electrode, which is common to the basic
chip assemblies and for each of the basic chip assemblies is
arranged on the lower side of the semiconductor body of that basic
chip assembly, is arranged on the solid assembly, wherein, for each
of the basic chip assemblies, an electrical current between the
individual upper main electrode and the individual or common lower
main electrode is controllable by means of its control
electrode.
23. The method of claim 22, wherein the control electrode
interconnection structure is electrically contacted by a connection
electrode which is passed through a feed-through formed in the
embedding compound.
24. The method of claim 23, wherein the feed-through is initially
produced in the cured embedding compound, and then the connection
electrode is introduced into the feed-through and is thereby
electrically conductively connected to the control electrode
interconnection structure.
25. The method of claim 24, wherein the feed-through is initially
produced in the cured embedding compound so that it extends
starting from a side edge of the solid assembly in a direction
perpendicular to the vertical direction into the embedding
compound.
26. The method of claim 24, wherein the connection electrode, when
it is introduced into the feed-through, contacts an electrically
conductive connection piece, which: is embedded in the embedding
compound; and is electrically conductively connected to the control
electrodes by the control electrode interconnection structure.
27. The method of claim 22, wherein the control electrode
interconnection structure: is formed as a prefabricated printed
circuit board; or is formed as a prefabricated electrically
conductive lead frame; or is produced by conformal deposition of an
electrically conductive material.
28. The method of claim 22, further comprising: providing an upper
contact plate and a lower contact plate; arranging the
semiconductor module between the upper contact plate and the lower
contact plate so that, for each of the basic chip assemblies: the
upper main electrode is electrically conductively connected to the
upper contact plate; and the lower main electrode is electrically
conductively connected to the lower contact plate.
29. A method for operating a semiconductor arrangement, the method
comprising: forming a semiconductor arrangement that comprises: an
upper contact plate and a lower contact plate; a number of basic
chip assemblies, each of which has: a semiconductor chip having a
semiconductor body, the semiconductor body having an upper side and
a lower side opposite the upper side, and the upper side being
separated from the lower side in a vertical direction; an
individual upper main electrode arranged on the upper side; and an
individual control electrode arranged on the upper side; wherein
the basic chip assemblies have either respectively a separate lower
main electrode, which is arranged on the lower side of the
semiconductor chip of the relevant basic chip assembly, or a common
lower main electrode, which for each of the basic chip assemblies
is arranged on the lower side of the semiconductor body of that
basic chip assembly; wherein, for each of the basic chip
assemblies, an electrical current between the individual upper main
electrode and the individual or common lower main electrode is
controllable by means of its control electrode; a dielectric
embedding compound, by which the basic chip assemblies are
connected to one another with a material bonded connection so as to
form a solid assembly; a control electrode interconnection
structure, which is embedded in the solid assembly and which
electrically conductively connects the control electrodes of the
basic chip assemblies to one another; providing an electrically
conductive upper pressure contact piece and an electrically
conductive lower pressure contact piece; clamping the semiconductor
arrangement between the upper pressure contact piece and the lower
pressure contact piece, such that there is a pure pressure contact
between the upper pressure contact piece and the upper contact
plate and there is a pure pressure contact between the lower
pressure contact piece and the lower contact plate; and connecting
the upper pressure contact piece and the lower pressure contact
piece to an electrical voltage source, so that different electrical
potentials are applied to the upper pressure contact piece and the
lower pressure contact piece.
Description
PRIORITY CLAIM
[0001] This application claims priority to German Patent
Application No. 10 2013 217 802.6, filed on 5 Sep. 2013, the
content of said German application incorporated herein by reference
in its entirety.
BACKGROUND
[0002] Semiconductor arrangements comprising press pack cells
currently available on the market have a complex structure for
connecting the semiconductor chips contained in the press pack
cells electrically to the main electrodes of the cell, for example
the emitter and collector, source and drain or anode and cathode,
and/or to the control electrodes, for example the gate or base.
[0003] There is therefore a need for an improved design of such
semiconductor arrangements, an improved production method and
operation of an improved semiconductor arrangement.
SUMMARY
[0004] A semiconductor arrangement comprises an upper contact plate
and a lower contact plate, as well as a number of basic chip
assemblies. Each of the basic chip assemblies has a semiconductor
chip having a semiconductor body, which has an upper side and a
lower side opposite the upper side, the upper side being separated
from the lower side in a vertical direction. Each of the basic chip
assemblies furthermore has an individual (i.e. belonging only to
the relevant basic chip assembly) upper main electrode arranged on
the upper side, and an individual (i.e. belonging only to the
relevant basic chip assemblies) control electrode arranged on the
upper side. Furthermore, either each of the basic chip assemblies
may have an individual (i.e. belonging only to the relevant basic
chip assemblies) lower main electrode, which is arranged on the
lower side of the semiconductor body of the semiconductor chip of
the relevant basic chip assemblies, or the basic chip assemblies
may have a common lower main electrode, which is arranged on the
lower side of each of the semiconductor bodies of the basic chip
assemblies.
[0005] With the aid of the control electrode, an electrical current
between the individual upper main electrode of this basic chip
assembly and the individual lower main electrode of this basic chip
assembly, or the common lower main electrode, can be controlled.
The current path between the upper main electrode and the lower
main electrode will also be referred to below as the "load
path".
[0006] In this case, main electrodes are intended to mean
electrodes between which a load current flows through the
semiconductor body during operation of the semiconductor chip. The
semiconductor chip may for example contain a diode or a MOSFET, an
IGBT, in general an IGFET, a bipolar transistor, a thyristor, or
any other controllable power semiconductor component. The upper and
lower main electrodes may generally be an anode and a cathode, a
cathode and an anode, a drain and a source, a source and a drain,
an emitter and a collector, or a collector and an emitter, of any
power semiconductor component integrated into the respective
semiconductor chip. The control electrode, for example a gate
terminal (for example of an MOSFET, IGBT, IGFET or thyristor) or a
base terminal (for example of a bipolar transistor, with the
exception of an IGBT) constitutes a control terminal by which a
load current between the respective upper main electrode and the
lower main electrode can be controlled. For each of the basic chip
assemblies, the control electrode is located on the upper side of
the semiconductor body.
[0007] The semiconductor arrangement furthermore comprises a
dielectric embedding compound, by which the basic chip assemblies
are connected to one another with a material bonded connection in
order to form a solid assembly. A control electrode interconnection
structure, which is embedded in the solid assembly, connects the
control electrodes of the basic chip assemblies to one another. To
this end, the dielectric embedding compound may extend continuously
between neighboring basic chip assemblies. Optionally, the
dielectric embedding compound may even extend continuously between
the semiconductor bodies of neighboring basic chip assemblies and
respectively directly adjoin these semiconductor bodies, i.e. their
semiconductor material.
[0008] In a method for producing a semiconductor module, a carrier
is provided, as well as a dielectric embedding compound and a
number of basic chip assemblies. Each of these basic chip
assemblies has a semiconductor chip having a semiconductor body,
the semiconductor body having an upper side and a lower side
opposite the upper side, and the upper side being separated from
the lower side in a vertical direction. Each of the basic chip
assemblies furthermore comprises an individual upper main electrode
arranged on the upper side and an individual control electrode
arranged on the upper side. The basic chip assemblies are arranged
next to one another on the carrier. The control electrodes are then
electrically conductively connected to one another by means of a
control electrode interconnection structure. The basic chip
assemblies arranged on the carrier and the control electrode
interconnection structure electrically connecting the control
electrodes are embedded into the embedding compound. The embedding
compound is subsequently cured so that the basic chip assemblies
with one another, and the control electrode interconnection
structure with the basic chip assemblies, are firmly connected to
one another by the embedding compound and the basic chip assemblies
together with the control electrode interconnection structure and
the embedding compound form a solid assembly. Furthermore, either
each of the basic chip assemblies provided has an individual lower
main electrode, which is arranged on the lower side of the
semiconductor body of the relevant basic chip assembly, or a lower
main electrode, which is common to the basic chip assemblies and
for each of the basic chip assemblies is arranged on the lower side
of the semiconductor body of this chip module. For each of the
basic chip assemblies, an electrical current between the individual
upper main electrode of the same chip module and the individual or
common lower main electrode can be controlled by means of its
control electrode.
[0009] Starting from a semiconductor module, which may have been
produced as explained above, a semiconductor arrangement having the
features mentioned above can be produced. To this end, an upper
contact plate and a lower contact plate are provided, and the
semiconductor module is arranged between the upper contact plate
and the lower contact plate in such a way that, for each of the
basic chip assemblies, the upper main electrode is electrically
conductively connected to the upper contact plate and the lower
main electrode is electrically conductively connected to the lower
contact plate.
[0010] In order to permit electrical operation of a semiconductor
arrangement, which is constructed and/or has been produced as
explained above, it may be clamped between an electrically
conductive upper pressure contact piece and an electrically
conductive lower pressure contact piece, in such a way that there
is a pressure contact between the upper pressure contact piece and
the upper contact plate, without the upper pressure contact piece
and the upper contact plate being connected with a material bonded
connection, and there is a pressure contact between the lower
pressure contact piece and the lower contact plate, without the
lower pressure contact piece and the lower contact plate being
connected with a material bonded connection. The upper pressure
contact piece and the lower pressure contact piece are connected to
an electrical voltage source, so that different electrical
potentials are applied to the upper pressure contact piece and the
lower pressure contact piece.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be explained below with the aid of
exemplary embodiments with reference to the appended figures. In
the figures, the same references refer to parts which are identical
or have the same effect.
[0012] FIGS. 1 to 29 show the production of a semiconductor
arrangement and of a semiconductor module according to a first
exemplary embodiment.
[0013] FIGS. 30 to 51 show the production of a semiconductor
arrangement and of a semiconductor module according to a second
exemplary embodiment.
[0014] FIGS. 52 to 75 show the production of a semiconductor
arrangement and of a semiconductor module according to a third
exemplary embodiment.
[0015] FIGS. 76 to 79 show various geometries of control electrode
interconnection structures for the production of a semiconductor
arrangement, in which control terminals of all the basic chip
assemblies are connected by connection lines of equal length to a
common control terminal point of the basic chip assemblies.
[0016] FIGS. 80 and 81 show various steps of a further method for
embedding a plurality of basic chip assemblies in an embedding
compound.
[0017] FIG. 82 shows a semiconductor arrangement, which is clamped
between two electrically conductive pressure pieces and is
electrically contacted by the latter.
DETAILED DESCRIPTION
[0018] A first exemplary embodiment of a semiconductor arrangement,
and a method for its production, will first be explained with the
aid of FIGS. 1 to 29.
[0019] FIG. 1 shows a semiconductor chip 1 as well as further
components for the production of a basic chip assembly 2 as
represented in FIG. 2. The semiconductor chip 1 comprises a
semiconductor body 10 made of a semiconductor base material, which,
in order to produce a power semiconductor component integrated into
the semiconductor body 10, contains in particular p-conductive and
n-conductive semiconductor zones. Furthermore, the semiconductor
chip 1 may also contain any desired number of electrically
conductive layers, for example for metallizations, silicide layers
or layers of doped polycrystalline semiconductor material (for
example polycrystalline silicon), as well as any desired number of
dielectric layers, for example nitride layers (for example silicon
nitride) or oxide layers (for example silicon oxide) or passivation
layers, for example imide layers. The semiconductor base material
may be any conventional semiconductor base material known for the
production of semiconductor components, for example any desired
elemental semiconductors (for example silicon, germanium), any
desired compound semiconductors (for example II-VI semiconductors
such as zinc selenide or cadmium sulfide, III-V semiconductors such
as gallium phosphide, gallium arsenide, indium phosphide, indium
antimonide, or IV-IV semiconductors such as silicon carbide or
silicon-germanium).
[0020] The semiconductor body 10 has an upper side 10t as well as a
lower side 10b opposite the upper side. The upper side 10t is
separated from the lower side 10b in a vertical direction v, the
vertical direction v extending perpendicularly to the lower side
10b. An upper main electrode 11 is arranged on the upper side 10t,
and a lower main electrode 12 is arranged on the lower side 10b.
There is likewise a control electrode 13 on the upper side 10t.
Furthermore, an optional upper dielectric passivation layer 15 may
be applied onto the upper side 10t. This passivation layer 15 may,
for example, be a polyimide.
[0021] The upper main electrode 11, the lower main electrode 12 and
the control electrode 13 may, for example, be thin metallization
layers. Such metallization layers may already be applied onto the
semiconductor body 10 during the production of the semiconductor
chip 1 at the wafer level with further identical semiconductor
chips 1, i.e. before the wafer is divided into mutually independent
semiconductor chips 1.
[0022] As represented in FIG. 2, on the side of the upper main
electrode 11 facing away from the semiconductor body 10 there is an
electrically conductive upper compensating die 21, which is
connected with a material bonded connection to the upper main
electrode 11 by means of an upper connecting layer 31.
Correspondingly, on the side of the lower main electrode 12 facing
away from the semiconductor body 10 there is an electrically
conductive lower compensating die 22, which is connected with a
material bonded connection to the lower main electrode 12 by means
of a lower connecting layer 32.
[0023] The compensating dies 21 and 22 are used, in particular, to
relieve mechanical stresses which occur when such compensating dies
21, 22 are pressure-contacted by a contact plate 41 or 42 explained
below (for example made of copper or aluminum), which has a thermal
expansion coefficient very different to the thermal expansion
coefficient of the semiconductor body 10. In the absence of
compensating dies 21, 22, the contact plate 41 or 42 would directly
contact the very thin main electrode 11 or 12, respectively. Owing
to the thermomechanical stresses resulting therefrom, in the best
case the electrical properties of the semiconductor chip 1 would be
modified, and in the least favorable case the semiconductor chip 1
may even tear.
[0024] The compensating dies 21 and 22 have (before mounting on the
upper main electrode 11 or the lower main electrode 12, and
immediately after mounting) relatively large thicknesses d21' and
d22' in the vertical direction v, for example at least 0.5 mm each,
at least 1 mm each or at least 1.5 mm each. The large thicknesses
are furthermore intended to avoid damage to the main electrodes 11
and 12 when the compensating plates 21 and 22 are ground, as will
be explained below.
[0025] Optionally, the upper compensating die 21 and/or the lower
compensating die 22 may have a linear thermal expansion coefficient
which is significantly less than the linear thermal expansion
coefficient of the upper main electrode 11 and of the lower main
electrode 12, in order to achieve adaptation of the linear thermal
expansion coefficient to the low linear thermal expansion
coefficient of the semiconductor body 10. For example, the upper
compensating die 21 and/or the lower compensating die 22 may have a
linear thermal expansion coefficient of less than 11 ppm/K, or even
less than 7 ppm/K, at a temperature of 20.degree. C. The upper
compensating die 21 and/or the lower compensating die 22 may in
this case, for example, consist of one of the following materials
or have one of the following structures: molybdenum; a metal matrix
composite material (MMC), for example AlSiC (aluminum silicon
carbide); a multilayer material having two or more metal layers,
for example a three-layer material having the layer sequence
copper-molybdenum-copper (Cu--Mo--Cu), for example with layer
thicknesses in the ratio 1:4:1, which gives an expansion
coefficient of the Cu--Mo--Cu three-layer material of about 7.3
ppm/K at a temperature of 20.degree. C.
[0026] The upper connecting layer 31 may, for example, be formed as
any desired solder layer, and in particular as a diffusion solder
layer, as a sintered layer, which contains a sintered metal powder
(for example silver powder or silver flakes), or an electrically
conductive adhesive layer. Independently thereof, the lower
connecting layer 32 may also be formed as any desired solder layer,
and in particular as a diffusion solder layer, as a sintered layer,
which contains a sintered metal powder (for example silver powder
or silver flakes), or an electrically conductive adhesive layer.
The upper connecting layer 31 and the lower connecting layer 32 may
in particular consist of the same material, although any desired
combinations of the materials mentioned for the two layers may also
be used.
[0027] In FIG. 1, the starting materials which are used for the
production of the upper connecting layer 31 and of the lower
connecting layer 32 are respectively denoted by 31' and 32'. This
is intended to mean that the original connecting means 31' and 32'
may be in a modified form after connection is established.
[0028] In the case of a starting material 31', 32' formed as a
solder (for example a solder containing tin), the resulting
connecting layer 31 or 32 may contain a material (for example
copper) which is diffused out of the upper main electrode 11, or
the lower main electrode 12, into the solder during the connecting
process, and therefore constitutes part of the final connecting
layer 31 or 32. In order to establish the connections, the solder
31', 32' may, for example, be applied onto the main electrodes 11,
12 and/or onto the compensating dies in the form of a solder paste
(for example by screen or template printing). Likewise, however, a
solder 31', 32' may also be inserted in the form of a prefabricated
solder platelet ("preform solder") between the upper compensating
die 21 and the upper main electrode 11, or between the lower
compensating die 22 and the lower main electrode 12. In each case,
in order to establish the aforementioned connections, the solder
paste or the solder platelet/platelets are melted and subsequently
cooled, so that a material-bonded connection is respectively formed
between the upper compensating die 21 and the upper main electrode
11, or between the lower compensating die 22 and the lower main
electrode 12, in the form of the upper connecting layer 31 or the
lower connecting layer 32.
[0029] In the case of a connecting layer 31 or 32 formed as a
sintered layer, the starting material 31' or 32' on which it is
based may be formed as a paste, which contains a metal powder (for
example silver powder or silver flakes), as well as a solvent. In
order to produce the connecting layers 31, 32, the paste may for
example be applied onto the main electrodes 11, 12 and/or onto the
compensating dies 21, 22 (for example by screen or template
printing). A paste layer formed from the paste is then arranged
between the upper main electrode 11 and the upper compensating die
21 and respectively contacts them, and/or a further paste layer
formed from the paste is arranged between the lower main electrode
12 and the lower compensating die 22 and respectively contacts
them. In this state, the paste layer or layers are dried by
evaporation of the solvent contained therein and then sintered, in
which case the sintering may take place at temperatures
significantly below 250.degree. C. As a result of the sintering,
the (electrically conductive) upper connecting layer 31 or the
(electrically conductive) lower connecting layer 32 is formed from
the two paste layers 31', 32'.
[0030] In the case of a connecting layer 31 or 32 formed as an
electrically conductive adhesive layer, the starting material 31'
or 32' on which it is based is formed as an electrically conductive
adhesive. In order to produce the connecting layers 31, 32, the
adhesive may for example be applied onto the main electrodes 11, 12
and/or onto the compensating dies 21, 22 (for example by screen or
template printing). An upper adhesive layer formed from the
adhesive is arranged between the upper main electrode 11 and the
upper compensating die 21 and respectively contacts them. As a
result of the subsequent curing, the electrically conductive upper
connecting layer 31 is formed from the upper adhesive layer.
Correspondingly, a lower adhesive layer formed from an adhesive is
arranged between the lower main electrode 12 and the lower
compensating die 22 and respectively contacts them. As a result of
the subsequent curing, the electrically conductive lower connecting
layer 32 is formed from the lower adhesive layer.
[0031] As is furthermore shown in FIG. 3 and in FIG. 4 in vertical
section, a plurality of basic chip assemblies 2, each of which has
a semiconductor chip 1 and as explained is fitted with an upper
compensating die 21 and a lower compensating die 22, are then
placed next to one another on the same side of a common carrier
300. Optionally, the placement--as shown--may be carried out in
such a way that, for all the basic chip assemblies 2, the upper
compensating dies 21 face away from the carrier 300. In principle,
however, in the case of one or more of the basic chip assemblies 2
the upper compensating dies 21 may also face away from the carrier
300, while in the case of one or more other of the basic chip
assemblies 2 the upper compensating dies 21 face toward the carrier
300.
[0032] The placement of the basic chip assemblies 2 on the carrier
300 may be carried out in such a way that they are in predetermined
positions relative to one another. In order to avoid slipping of
the placed basic chip assemblies 2, the surface of the carrier 300
may be formed in such a way that the basic chip assemblies 2 adhere
thereon. To this end, for example, the carrier 300 may be provided
with an adhesive film on which the basic chip assemblies 2 are
placed.
[0033] As is furthermore shown in FIG. 5, after the placement of
the basic chip assemblies 2 on the carrier 300, a control electrode
interconnection structure 70 is provided, onto which the basic chip
assemblies 2 fixed on the carrier 300 are applied in such a way
that the control electrodes 13 of the basic chip assemblies 2 are
electrically conductively connected to one another by the control
electrode interconnection structure 70. The control electrode
interconnection structure 70 may for example be formed as a
prefabricated printed circuit board in the form of a grid, or as a
prefabricated electrically conductive lead frame. In each case, the
control electrode interconnection structure 70 has a conductor
structure 72, as shown in the enlarged detail A according to FIG. 6
and by the vertical section through the detail A according to FIG.
7. In the case of a printed circuit board, the conductor structure
72 may be formed by surface-wide metallization of a dielectric
carrier (for example FR-4). In the case of an electrically
conductive lead frame, the conductor structure 72 may, for example,
be produced by stamping a metal sheet. The electrically conductive
connection between the conductor structure 72 of the control
electrodes 13 may be established by means of a connecting layer 33
(see FIG. 10), for example a solder, a layer of a sintered metal
powder, an electrically conductive adhesive or a pure pressure
contact.
[0034] In the arrangement according to FIG. 10, the control
electrode interconnection structure 70 bears directly on the
passivation layer 15. As an alternative to this, the control
electrode interconnection structure 70 and/or the conductor
structure 72 of the control electrode interconnection structure 70
may also be separated from the passivation layer 15. The free space
then formed between the passivation layer 15 and the control
electrode interconnection structure 70, or between the passivation
layer 15 and the conductor structure 72, would subsequently be
filled with embedding compound 4. In order to ensure the required
electrical connection between the control electrode interconnection
structure 70, or a conductor structure 72 of the control electrode
interconnection structure 70, and the control electrode 13, the
connecting layer 33 would need to be made correspondingly thicker,
and/or the control electrode interconnection structure 70 or its
conductor structure 72 would need to have an extension above the
control electrode 13, which extends in the direction of the control
electrode 13.
[0035] Optionally, before, during or after the connection of the
control electrode interconnection structure 70 to the control
electrodes 13, an electrically conductive connection piece 78 may
be applied onto the control electrode interconnection structure 70
and electrically conductively connected to the conductor structure
72, which may be done by means of a solder, a layer of a sintered
metal powder, an electrically conductive adhesive, by welding or by
ultrasonic bonding.
[0036] FIGS. 8 and 9 respectively show a plan view and a vertical
section corresponding to FIGS. 3 and 4, but after mounting of the
control electrode interconnection structure 70 on the control
electrodes 13. The representation is merely to be understood as
schematic. In particular, FIG. 9 is intended to show that (because
of the upper compensating die 21) the basic chip assemblies 2 may
extend beyond the control electrode interconnection structure 70 in
the vertical direction v. FIG. 10 represents an enlarged detail of
the view according to FIG. 9. The connecting layer 33 explained
above is also shown therein.
[0037] As is furthermore shown by FIG. 11, after establishment of
the electrically conductive connection between the control
electrode interconnection structure 70 and the control electrodes
13, a viscous embedding compound 4 is applied over the basic chip
assemblies 2 located on the carrier 300. The embedding compound 4
is then, as represented in FIG. 12, pressed against the carrier 300
by means of a die 310, in such a way that at least the intermediate
spaces lying between respectively neighboring basic chip assemblies
2 are filled with the embedding compound 4.
[0038] The embedding compound 4 is then cured, so that the basic
chip assemblies 2 embedded in the embedding compound 4 form a solid
assembly 5 together with the embedding compound 4. As is
furthermore shown in FIG. 13, after the curing of the embedding
compound 4, the die 310 may be raised from the solid assembly 5 and
the assembly 5 may be removed from the carrier 300. FIG. 14 shows
the assembly 5 then obtained. The effect of the embedding compound
4, which is dielectric at least in the cured state, is that the
basic chip assemblies 2 are connected to one another firmly and
with a material bonded connection. For example, polycondensed
polymers (for example an epoxy resin or a polyurethane-based
encapsulation material) are suitable as the embedding compound. In
principle, however, any desired embedding compound 4 may be used
for all configurations of the invention, so long as they are
dielectric in the cured state. In particular, according to the
present invention an embedding compound may be formed from a
homogeneous material or a homogeneous material mixture.
[0039] An upper cover layer 51 of the assembly 5 may now be removed
from the assembly 5, so that a residual assembly 6 remains of the
assembly 5 (see FIG. 15). Optionally, the assembly 5 may be brought
into a desired geometrical shape before or after the removal of the
cover layer 51, for example by form milling. In this regard, FIG.
16 represents by way of example a residual assembly 6 which has an
essentially rectangular base contour, which is shown in plan view
according to FIG. 18, in which the upper compensating dies 21 can
also be seen. FIG. 17 also shows an enlarged detail of the view
according to FIG. 16.
[0040] The production will be explained below with reference to the
structure according to FIGS. 16 to 18. The further production
could, however, also be carried out in the same way starting from
the arrangement according to FIG. 15. Possibly desired adaptation
to a desired geometrical shape may then be carried out at a later
time.
[0041] In each case, the effect of the embedding compound 4 is that
the basic chip assemblies 2 are firmly connected to one another in
a residual assembly 6 as well. In this case, the embedding compound
4 may optionally bear directly on the semiconductor body 10 of each
of the basic chip assemblies 2, i.e. on the semiconductor material
thereof. The embedding compound 4 may in this case extend
continuously between the semiconductor bodies 10 of the
semiconductor chips 1 of neighboring basic chip assemblies 2.
[0042] FIG. 19 shows the arrangement according to FIG. 18, as well
as the profile of the control electrode interconnection structure
70 covered by the embedding compound 4 and therefore only
represented by dashes. The representation according to FIG. 20
corresponds to the representation according to FIG. 19, but with a
view of the opposite side, so that the lower compensating dies 22
can be seen in this case. The profile of the control electrode
interconnection structure 70 covered by the embedding compound 4 is
again represented by dashes.
[0043] FIG. 21 shows an enlarged detail B, shown in FIG. 19, with a
chip module 2. The lateral border of the semiconductor body 10,
covered by the embedding compound 4, of the semiconductor chip 1 of
the basic chip assembly 2 is represented therein by means of a
dot-and-dash line. The lateral border of the control electrode 13,
likewise covered by the embedding compound 4, is represented by
means of a dotted line. On the other hand, the profile of the
control electrode interconnection structure 70 is not
represented.
[0044] FIG. 22 shows an enlarged detail C, shown in FIG. 19, with a
section of the side edge 6r of the residual assembly 6, or of the
embedding compound 4. The lateral border of the optional
electrically conductive connection piece 78, covered by the
embedding compound 4, is represented therein by means of a
dot-and-dash line. The profile of the control electrode
interconnection structure 70, likewise covered by the embedding
compound 4, is represented by means of a dotted line.
[0045] If an electrically conductive connection piece 78 is
provided, it may be electrically contacted from outside the
residual assembly 6 by a connection electrode 75, which is passed
through a feed-through formed in the embedding compound 4, for
example as a bore or as a groove. An example of this is shown by
FIGS. 23 and 24, which correspond to the detail C according to
FIGS. 19 and 22. As initially shown in FIG. 23, the connection
piece 78 embedded in the embedding compound 4 may be drilled
through the cured embedding compound 4, so that a feed-through 44
formed as a bore is obtained. Likewise, instead of a bore, a groove
may be milled into the embedding compound 4, and optionally also
into the connection piece 78 embedded therein. In each case, the
feed-through 44 may extend starting from the side edge 6r of the
residual assembly 6, or of the embedding compound 4, in a direction
perpendicular to the vertical direction v into the embedding
compound 4, at least as far as the connection piece 78.
[0046] As is furthermore shown in FIG. 24, a connection electrode
75 may then be inserted into the feed-through 44, so that it
electrically contacts the connection piece 78. The connection
electrode 75 may for example be a screw, which is screwed into the
bore formed with a reduced dimension relative to the external screw
thread of the screw, in such a way that the external screw thread
cuts into the connection piece 78. As an alternative, an internal
screw thread which matches the external screw thread of the screw,
and extends into the connection piece 78, may also be cut first
into the bore, and the screw 75 may then be screwed into the
internal screw thread as far as the connection piece 78. A further
alternative is to insert the soldered tip of a connection electrode
75 into the feed-through 44 and then to solder the connection
electrode 75 to the connection piece 78. The heat required for the
soldering may be supplied via the connection electrode 75. It is
likewise possible to connect the connection electrode 75
mechanically and electrically conductively to the connection piece
78 by means of an electrically conductive adhesive.
[0047] As is likewise represented in FIG. 24, the connection
electrode 75 may be used in order to fasten a control line 9 to the
residual assembly 6. By means of such a control line 9, the control
electrodes 13 may be supplied during subsequent operation with an
electrical control signal, for example a "high" level or a "low"
level, for example in order to set the load path in a conductive or
blocking state.
[0048] As an alternative to a connection piece 78, which as
described is connected electrically conductively and optionally
also with a material bonded connection to a conductor structure 72
of the control electrode interconnection structure 70, the
conductor structure 72 may also be electrically contacted directly
by a connection electrode 75 in a manner described with the aid of
FIGS. 23 and 24, and/or electrically connected to a control line 9.
In this case, the conductor structure 72 itself fulfills the
function of the connection piece 78.
[0049] FIG. 25 shows an exploded representation of the finished
semiconductor arrangement 7 shown in FIG. 29, FIGS. 26 and 27 show
the semiconductor arrangement 7 during its assembly, and FIG. 28
shows a plan view of the arrangement according to FIG. 29, but
without the upper contact plate 41. As revealed by these FIGS. 25
to 29, the semiconductor arrangement 7 comprises a residual
assembly 6 with a feed-through 44, an electrically conductive upper
contact plate 41, an electrically conductive lower contact plate
42, and a spacer ring 50. The residual assembly 6 could be provided
with a connection electrode 75 and/or a control line 9, as
explained with reference to FIGS. 23 and 24.
[0050] The residual assembly 6 with the control electrode
interconnection structure 70 embedded in the embedding compound 4
is arranged between the upper contact plate 41 of the lower contact
plate 42. The upper contact plate 41 is used to electrically and
mechanically contact the compensating die 21, 22 (here the upper
compensating die 21), facing toward the upper contact plate 41, of
each of the basic chip assemblies 2. To this end, for each of the
basic chip assemblies 2, the upper contact piece 41 has an upper
contact elevation 411 (see FIG. 26), which electrically and
mechanically contacts one of the compensating dies 21, 22 (here the
upper compensating die 21) of the relevant chip module 2.
[0051] Correspondingly, the lower contact plate 42 is used to
electrically and mechanically contact the compensating die 21, 22
(here the lower compensating die 22), facing toward the lower
contact plate 42, of each of the basic chip assemblies 2. To this
end, for each of the basic chip assemblies 2, the lower contact
piece 42 has a lower contact elevation 421, which electrically and
mechanically contacts one of the compensating dies 21, 22 (here the
lower compensating die 22) of the relevant chip module 2.
[0052] Copper for example, which may optionally be provided with a
thin nickel layer on the surface, is suitable as material for the
upper contact piece 41 and/or the lower contact piece 42. In
principle, however, any other desired electrically conductive
materials, in particular metals or metal alloys, may be used, for
example aluminum or an aluminum alloy or a copper alloy, with or
without a coating.
[0053] In the example shown, for each of the basic chip assemblies
2 of the semiconductor arrangement 7, the upper contact die 21 lies
on the side of the basic chip assembly 2 facing toward the upper
contact plate 41, and the lower contact die 22 lies on the side of
the basic chip assembly 2 facing toward the lower contact plate
42.
[0054] In contrast, other semiconductor arrangements may have a
first subset of the basic chip assemblies 2 and a second subset of
the basic chip assemblies 2, wherein for each of the basic chip
assemblies 2 of the first subset, the upper contact die 21 lies on
the side of the basic chip assembly 2 facing toward the upper
contact plate 41 and the lower contact die 22 lies on the side of
the basic chip assembly 2 facing toward the lower contact plate 42,
and wherein for each of the basic chip assemblies 2 of the second
subset, the upper contact die 21 lies on the side of the basic chip
assembly 2 facing toward the lower contact plate 42 and the lower
contact die 22 lies on the side of the basic chip assembly 2 facing
toward the upper contact plate 41.
[0055] It is likewise possible that, for each of the basic chip
assemblies 2 of a semiconductor arrangement, the upper contact die
21 lies on the side of the basic chip assembly 2 facing toward the
lower contact plate 42, and the lower contact die 22 lies on the
side of the basic chip assembly 2 facing toward the upper contact
plate 41.
[0056] The spacer ring 50, which is arranged between the contact
plates 41 and 42 and annularly surrounds the residual assembly 6,
consists of a dielectric material, for example ceramic. In this
way, an electrical short circuit between the contact plates 41 and
42 is prevented. As also in all other configurations of the
invention, the spacer ring 50 may be connected with a material
bonded connection both to the upper contact plate 41 and to the
lower contact plate 42, for example by soldering, adhesive bonding
or sintering.
[0057] As an alternative or in addition to a control electrode
interconnection structure 70, which is arranged as explained above
between the semiconductor chips 1 of the basic chip assemblies 2
and the upper contact plate 41, the control electrode
interconnection structure 70, or a further control electrode
interconnection structure, could also be arranged in a
corresponding way between the semiconductor chips 1 of the basic
chip assemblies 2 and the lower contact plate 42, in order to
electrically connect control electrodes 13 which may optionally be
arranged on the side of the semiconductor body 10 facing toward the
lower contact piece 42.
[0058] If there is at least one control electrode interconnection
structure 70, for each of the control electrode interconnection
structures 70 a connection electrode 75 and/or an electrically
conductive control line 9 (see FIGS. 23, 24 and 27 to 29) may be
provided in order to be able to electrically contact the relevant
control electrode interconnection structure 70 from outside the
finished semiconductor arrangement 7 (see FIG. 29). In this case,
each such control electrode interconnection structure 70 may,
independently of the configuration of another control electrode
interconnection structure 70, as explained with the aid of FIGS. 23
and 24, be electrically contacted from outside the residual
assembly 6 by an electrically conductive connection piece 78,
connected electrically conductively and optionally also with a
material bonded connection to a conductor structure 72, or the
conductor structure 72 of this control electrode interconnection
structure 70 may itself fulfill the function of the connection
piece 78.
[0059] In each case, a connection electrode 75 or, as represented
in FIGS. 27 and 29, a control line 9, may be passed through an axis
opening or groove 55 formed in the spacer ring 50 (see FIGS. 25 and
26) as far as the outside of the semiconductor arrangement 7.
Inside the spacer ring 50, the control line 9 (and/or the
connection electrode 75) is electrically conductively connected to
the control electrode interconnection structure 70 and therefore to
the control electrodes 13. If a connection electrode 75, for
example a screw, is used, this may be passed not only through the
feed-through 44 but also through the axis opening or groove 55. In
the case of a screw, it may have a screw head which bears on the
spacer ring 50 directly or indirectly, for example via a washer,
when the screw is screwed into a connection piece 78 or into a
conductor structure 72 of the control electrode interconnection
structure 70.
[0060] A second exemplary embodiment of a semiconductor
arrangement, and a method for its production, will subsequently be
explained with the aid of FIGS. 30 to 51. While in the first
exemplary embodiment the semiconductor chips 1 of the basic chip
assemblies 2 were respectively provided with an upper compensating
die 21 and a lower compensating die 22 before embedding in the
embedding compound 4, in the second exemplary embodiment the
semiconductor chips 1 are respectively provided only with one
compensating die before the embedding. This compensating die may
respectively be the upper compensating die 21, but also the lower
compensating die 22. In the following figures, this will be
explained with reference to the example of the lower compensating
die 22.
[0061] FIG. 30 shows a semiconductor chip 1 as well as further
components for the production of a basic chip assembly 2 as
represented in FIG. 31. The semiconductor chip 1 may be formed
like, or produced in the same way as, the semiconductor chip 1 of
the first exemplary embodiment.
[0062] As represented in FIG. 31, on the side of the lower main
electrode 12 facing away from the semiconductor body 10 there is an
electrically conductive lower compensating die 22, which is
connected with a material bonded connection to the lower main
electrode 12 by means of a lower connecting layer 32.
[0063] The lower compensating die 22 is used for the same purpose
and may have the same properties as, and may be connected to the
lower main electrode 12 in the same way as, the lower compensating
die 22 according to the first exemplary embodiment. Accordingly,
the lower connecting layer 32 may have the same structure, and be
produced in the same way and from the same starting materials 32',
as the lower connecting layer 32 according to the first exemplary
embodiment.
[0064] FIG. 32 shows the arrangement according to FIG. 31 in an
inverted position. In this position, as is furthermore shown in
FIG. 33, a plurality of basic chip assemblies 2, each of which has
a structure as explained with the aid of FIGS. 30 and 31, are
placed next to one another on the same side of a common carrier 300
in such a way that the upper sides 10t of the semiconductor chips 1
of the basic chip assemblies 2 face toward the carrier 300.
[0065] Optionally, an electrically conductive connection piece 78
as described above may also be placed next to the basic chip
assemblies 2 on the carrier 300.
[0066] The placement of the basic chip assemblies 2, and optionally
of the connection piece 78, on the carrier 300 may be carried out
in such a way that they are in predetermined positions relative to
one another. In order to avoid slipping of the placed basic chip
assemblies 2, the surface of the carrier 300 may be formed in such
a way that the basic chip assemblies 2, and optionally the
connection piece 78, adhere thereon. To this end, for example, the
carrier 300 may be provided with an adhesive film on which the
basic chip assemblies 2, and optionally the connection piece 78,
are placed. FIG. 34 shows an enlarged detail of the arrangement
according to FIG. 33 with one of the basic chip assemblies 2 fixed
on the carrier 300.
[0067] As is furthermore shown in FIG. 35, after the placement of
the basic chip assemblies 2, and optionally of the connection piece
78, on the carrier 300, a viscous embedding compound 4 is applied
over the basic chip assemblies 2, and optionally the connection
piece 78, located on the carrier 300. The embedding compound 4 is
then, as represented in FIG. 36, pressed against the carrier 300 by
means of a die 310, in such a way that at least the intermediate
spaces lying between respectively neighboring basic chip assemblies
2 are filled with the embedding compound 4.
[0068] The embedding compound 4 is then cured, so that the basic
chip assemblies 2 embedded in the embedding compound 4 form a solid
assembly 5 together with the embedding compound 4. As is
furthermore shown in FIG. 37, after the curing of the embedding
compound 4 the die 310 may be raised from the solid assembly 5 and
the assembly 5 may be removed from the carrier 300. FIG. 38 shows
the assembly 5 then obtained. The effect of the embedding compound
4, which is dielectric at least in the cured state, is that the
basic chip assemblies 2 are connected to one another firmly and
with a material bonded connection. The embedding compound 4 may
consist of the same materials, or be processed in the same way, and
have the same properties, as the embedding compound 4 of the first
exemplary embodiment.
[0069] FIG. 39 shows the arrangement according to FIG. 38 inverted,
FIG. 40 shows an enlarged detail of the arrangement according to
FIG. 39 with one of the basic chip assemblies 2 embedded in the
embedding compound 4, and FIG. 41 shows a plan view of the entire
assembly 5 according to FIG. 39 with a view of the upper main
contacts 11 and the control contacts 13. It can be seen from FIGS.
40 and 41 that the upper main electrodes 11 and the control
electrodes 13 are not covered by the embedding compound 4, which
results from the fact that they face toward the carrier 300 during
the embedding in the embedding compound 4 and are protected by the
carrier 300 from contact with the embedding compound 4. The upper
main electrodes 11 and the control electrodes 13 are therefore
exposed, so that they can be readily contacted electrically.
Optionally, a careful cleaning step may also be carried out in
order to free the upper main electrodes 11 and the control
electrodes 13 of possible contamination.
[0070] As is furthermore shown in FIG. 42, a control electrode
interconnection structure 70 is applied onto the assembly 5
according to FIG. 41 in such a way that the control electrodes 13
of the basic chip assemblies 2, and optionally the connection piece
78, are electrically conductively connected to one another by a
conductor structure 72 of a control electrode interconnection
structure 70, and therefore by the control electrode
interconnection structure 70.
[0071] The control electrode interconnection structure 70 may again
be formed, for example, as a prefabricated printed circuit board in
the form of a grid, or as a prefabricated electrically conductive
lead frame, placed on the assembly 5 and electrically conductively
connected to the control electrodes 13, and optionally to the
connection piece 78. The corresponding electrically conductive
connections may for example be established by means of a solder or
a layer of a sintered metal powder, or an electrically conductive
adhesive. In the case of an electrically conductive lead frame, the
conductor structure 72 may for example be produced by stamping a
metal sheet.
[0072] Instead of applying the control electrode interconnection
structure 70 as a prefabricated unit onto the assembly 5, the
conductor structure 72 of the control electrode interconnection
structure 70 may also be applied onto the assembly 5 by a
deposition method, and optionally covered with a dielectric layer
73, as shown by way of example below with the aid of FIGS. 43 and
44.
[0073] FIG. 43 shows an enlarged vertical section through a section
of the assembly 5 with the conductor structure 72, applied thereon,
of the control electrode interconnection structure 70. The position
of the connection piece 78 covered by the embedding compound is
represented by dashes. The conductor structure 72 contacts each of
the control electrodes 13, and it extends above the connection
piece 78 (if there is one) and likewise contacts the latter. The
control electrodes 13 are therefore electrically conductively
connected to one another as well as optionally to the connection
piece 78.
[0074] The conductor structure 72 may for example be produced by
depositing an electrically conductive material, for example a metal
or a doped polycrystalline semiconductor material, onto the
assembly 5. The deposition may, for example, be carried out by a
chemical and/or physical deposition method, for example PVD
(PVD=physical vapor deposition) CVD (CVD=chemical vapor
deposition), by sputtering or by electrical or non-electrical
plating. The deposition may be carried out conformally. The
finished deposited conductor structure 72 may for example have a
thickness in the range of from 30 .mu.m to 70 .mu.m.
[0075] In each of the methods mentioned above, a continuous layer
of the electrically conductive material may first be produced on
the assembly 5 and then structured, for example
photolithographically by means of a mask. It is likewise possible
first to apply a mask layer onto the assembly 5, to structure the
mask layer so that it has openings, and then to apply the
electrically conductive material onto the structured mask layer, so
that the electrically conductive material lies on the assembly 5 in
the region of the mask openings and electrically conductively
connects the control electrodes 13, and optionally the connection
piece 78, to one another so as to form the conductor structure
72.
[0076] In order to avoid electrical discharges between the
conductor structure 72 of the control electrode interconnection
structure 70 through the passivation 15, the passivation 15 may be
used with a sufficient thickness, or an additional dielectric layer
may optionally also be applied onto the passivation layer 15 before
the deposition of the conductor structure 72. The additional
dielectric layer would then be arranged between the passivation
layer 15 and the conductor structure 72. The additional dielectric
layer could likewise be applied onto the assembly 5 by conformal
deposition. The upper main electrodes 12 would consequently not be
covered, or at least not be covered completely, by the additional
dielectric layer. In the case of surface-wide deposition of the
additional dielectric layer, it would need to be opened in the
region of the upper main electrodes 12 in order to permit their
contacting. Organic polymers, polyimide, epoxy resin or silicone,
for example, are suitable as materials for such an additional
dielectric layer.
[0077] As is furthermore shown as a result in FIG. 44, a further,
for example dielectric, layer 73 may optionally be applied onto the
conductor structure 72 in order to electrically insulate it. The
application of such a layer 73 may be carried out by any available
technique. For example, a dielectric material may be applied onto
the conductor structure 72 by deposition (for example PVD or CVD or
sputtering). It is likewise possible to place or adhesively bond a
stamped dielectric plate or a dielectric film onto the conductor
structure 72.
[0078] After the production of the assembly 5, it is not only
possible to apply a control electrode interconnection structure 70
onto the assembly 5, but the upper main electrodes 11 may also
respectively be provided with an upper compensating die 21, as
represented in FIGS. 45 and 46.
[0079] The upper compensating die 21 is used for the same purpose
and may have the same properties as, and may respectively be
connected to one of the upper main electrodes 11 in the same way
as, the upper compensating die 21 according to the first exemplary
embodiment. Accordingly, the upper connecting layers 31 may have
the same structure, and be produced in the same way and from the
same starting material 31', as the upper connecting layer 31
according to the first exemplary embodiment. By an upper
compensating die 21 being connected in this way to a semiconductor
chip 1, it forms a part of the relevant basic chip assembly 2.
[0080] Before or after the application of the upper compensating
dies 21, and before or after the application of the control
electrode interconnection structure 70, the assembly 5 may
optionally be applied onto a carrier 320 in such a way that the
lower sides 10b of the semiconductor bodies 10 face toward the
carrier 320, which is shown as a result in FIG. 46.
[0081] A further embedding compound 4' may then in turn in the same
way be applied onto this arrangement, and then cured, as already
explained with the aid of FIGS. 11 to 13 for the application of the
embedding compound 4 onto the basic chip assemblies 2 located on
the carrier 300. The embedding compound 4' may in this case have
the same properties as the embedding compound 4. The embedding
compound 4' and the embedding compound 4 may be identical or
different.
[0082] As a result, an assembly 5' is obtained, as represented in
FIG. 47 in detail (still on the carrier 320) and in FIG. 48 as a
whole (separated from the carrier 320). FIGS. 47 and 48 show the
assembly 5' before the removal here both of an upper cover layer 51
and of a lower cover layer 52. After the removal of these cover
layers 51 and 52, a residual assembly 6 remains, as represented in
FIG. 49 as a whole and in FIG. 50 as an enlarged detail.
[0083] In FIGS. 47 and 48, the plane E1 indicates the interface
between the upper cover layer 51 and the residual assembly 6.
Correspondingly, the plane E2 indicates the interface between the
lower cover layer 52 and the residual assembly 6. The planes E1 and
E2 preferably extend parallel to one another.
[0084] By the removal of the upper cover layer 51 and the lower
cover layer 52 from the assembly 5', the cured embedding compounds
4, 4' are partially removed from the assembly 5'. Furthermore, for
each of the basic chip assemblies 2, the upper compensating die 21
and the lower compensating die 22 of the relevant basic chip
assembly 2 are respectively removed partially from the assembly
5'.
[0085] In each case, the embedding compound 4 and/or the further
embedding compound 4' also ensure after the removal of the upper
cover layer 51 and the lower cover layer 52 that the semiconductor
chips 1 are connected to one another firmly and with a material
bonded connection, and together with the embedding compound 4 form
the residual assembly 6.
[0086] The removal of the upper cover layer 51 and the lower cover
layer 52 may, for example, be carried out by processing (grinding,
polishing, lapping, etc.) of the assembly 5' in a conventional
wafer grinding system. The effect achievable by this is that the
residual assembly 6 (apart from minor dishing effects) has
plane-parallel surfaces 6t and 6b, on which the (ground) upper
compensating dies 21 and the (ground) lower compensating dies 22
adjoin flush with the embedding compound 4.
[0087] After the removal of the upper cover layer 51 and the lower
cover layer 52, the semiconductor chips 1, the upper connecting
layers 31 and the lower connecting layers 32 of each of the basic
chip assemblies 2 remain in the residual assembly 6. Furthermore,
for each of the basic chip assemblies 2, the residue of the upper
compensating die remaining after the removal of the upper cover
layer 51 and the residue of the lower compensating die 22 remaining
after the removal of the lower cover layer 52 are exposed.
[0088] After the removal of the upper cover layer 51, the thickness
d21 of the upper compensating die 21 is reduced relative to its
original thickness d21' (see FIG. 45), for example by about 0.1 mm.
The reduced thickness d21 may, however, still be for example at
least 0.4 mm, at least 0.9 mm or at least 1.4 mm.
[0089] Furthermore, the thickness d22 of the lower compensating die
22 is reduced by the removal of a lower cover layer 52 relative to
its original thickness d22' (see FIG. 30), for example by about 0.1
mm. The reduced thickness d22 may, however, still be for example at
least 0.4 mm, at least 0.9 mm or at least 1.4 mm.
[0090] As a result, for the residual assembly 6, in the same way as
for the residual assembly 6 of the first exemplary embodiment (FIG.
16), optionally after form milling to produce a desired geometry,
the connection piece 78 covered by the embedding compound 4, 4', or
the control electrode interconnection structure 70 covered by the
embedding compound 4, 4', or its conductor structure 72, may be
electrically contacted by a connection electrode 75 and/or by a
control line 9, as already explained with the aid of the first
exemplary embodiment.
[0091] Furthermore, the residual assembly 6 may be arranged between
an electrically conductive upper contact plate 41 and an
electrically conductive lower contact plate 42, and optionally
inside a dielectric spacer ring 50, in such a way that the upper
contact plate 41 of each of the basic chip assemblies 2
electrically and mechanically contacts the compensating die 21, 22
(here the upper compensating die 21) facing toward the upper
contact plate 41, and the lower contact plate 42 of each of the
basic chip assemblies 2 electrically and mechanically contacts the
compensating die 21, 22 (here the lower compensating die 22) facing
toward the lower contact plate 42.
[0092] The upper contact piece 41 and the lower contact piece 42
may have the same properties, and consist of the same materials, as
the upper contact piece 41 and the lower contact piece 42 of the
first exemplary embodiment. FIG. 51 shows the finished
semiconductor arrangement 7.
[0093] A third exemplary embodiment of a semiconductor arrangement,
and a method for its production, will subsequently be explained
with the aid of FIGS. 52 to 75. While in the first exemplary
embodiment the semiconductor chips 1 of the basic chip assemblies 2
were respectively provided with two compensating dies 21 and 22
before the embedding in the embedding compound 4, and were
respectively provided with one compensating die 22 in the second
exemplary embodiment, the semiconductor chips 1 in the third
exemplary embodiment are not provided with a compensating die
before the embedding. Rather, the semiconductor chips 1 are
provided with compensating dies 21 and 22 after the semiconductor
chips 1 have been embedded in the embedding compound 4. The
semiconductor chips 1 then respectively form a basic chip assembly
2.
[0094] FIG. 52 shows a semiconductor chip 1, which, apart from the
lack of a lower main electrode 12, may be formed like, or produced
in the same way as, the semiconductor chip 1 of the first exemplary
embodiment. The lower side 10b of the semiconductor body 10 is thus
exposed, i.e. it is formed by the semiconductor material of the
semiconductor body 10.
[0095] FIG. 53 shows the semiconductor chip 1 according to FIG. 51
in an inverted position. In this position, as furthermore shown in
FIG. 54, a plurality of semiconductor chips 1 are placed next to
one another on the same side of a common carrier 300 in such a way
that the upper sides 10t of the semiconductor chips 1 face toward
the carrier 300. FIG. 55 shows an enlarged detail of the
arrangement according to FIG. 54 with a semiconductor chip 1 fixed
on the carrier 300. As likewise represented in FIG. 54, an
electrically conductive connection piece 78, as described above,
may optionally also be placed on the carrier 300 next to the
semiconductor chips 1.
[0096] The placement of the semiconductor chips 1, and optionally
of the connection piece 78, on the carrier 300 may be carried out
in such a way that they are in predetermined positions relative to
one another. In order to avoid slipping of the placed basic chip
assemblies 2, the surface of the carrier 300 may be formed in such
a way that the semiconductor chip 1, and optionally the connection
piece 78, adhere thereon. To this end, for example, the carrier 300
may be provided with an adhesive film on which the semiconductor
chips 1, and optionally the connection piece 78, are placed.
[0097] As is furthermore shown in FIG. 56, after the placement of
the semiconductor chips 1, and optionally of the connection piece
78, on the carrier 300, a viscous embedding compound 4 is applied
over the semiconductor chips 1, and optionally the connection piece
78, located on the carrier 300.
[0098] The embedding compound 4 is then, as represented in FIG. 57,
pressed against the carrier 300 by means of a die 310, in such a
way that at least the intermediate spaces lying between
respectively neighboring semiconductor chips 1 are filled with the
embedding compound 4.
[0099] The embedding compound 4 is then cured, so that the
semiconductor chips 1 embedded in the embedding compound 4 form a
solid assembly 5 together with the embedding compound 4.
[0100] As is furthermore shown in FIG. 58, after the curing of the
embedding compound 4 the die 310 may be raised from the solid
assembly 5 and the assembly 5 may be removed from the carrier
300.
[0101] FIG. 59 shows the assembly 5 then obtained. The effect of
the embedding compound 4, which is dielectric at least in the cured
state, is that the semiconductor chips 1 are connected to one
another firmly and with a material bonded connection. The embedding
compound 4 may consist of the same materials, or be processed in
the same way, and have the same properties, as the embedding
compound 4 of the first exemplary embodiment.
[0102] FIG. 59 shows the assembly 5 before removal of a lower cover
layer 52. Since the semiconductor bodies 10 are inverted in the
assembly, the lower cover layer 52 lies on top. After removal of
this cover layer 52, a residual assembly 6 remains, as represented
in FIG. 60. In FIG. 59, the plane E2 indicates the interface
between the lower cover layer 52 and the residual assembly 6. The
plane E2 defines the lower side 6b of the residual assembly 6, and
it preferably extends parallel to the upper side 6t of the residual
assembly.
[0103] By the removal of the lower cover layer 52 from the assembly
5, which may for example be carried out by processing (grinding,
polishing, lapping, etc.) of the assembly 5 in a conventional wafer
grinding system, the cured embedding compounds 4 are partially
removed from the assembly 5. In each case, the embedding compound 4
also ensures after the removal of the lower cover layer 52 that the
semiconductor chips 1 are connected to one another firmly and with
a material bonded connection, and together with the embedding
compound 4 form the residual assembly 6. After the removal of the
lower cover layer 52, the semiconductor chips 1 thus remain in the
residual assembly 6.
[0104] As is furthermore shown with the aid of FIGS. 61 to 66, an
optional metallization level 92 is applied onto the lower side 6b
of the residual assembly 6, which is for example done by a
deposition method, for example by a chemical and/or physical
deposition method, for example PVD (PVD=physical vapor deposition)
or may be done by CVD (CVD=chemical vapor deposition), by
sputtering or non-electrical plating.
[0105] The applied metallization level 92 may, as shown in FIGS. 61
and 62, be applied as a continuous layer, or, as shown in FIGS. 63
and 64, as a structured layer. In the case of a structured layer,
the structuring may be selected in such a way that all sections of
the metallization level 92 exclusively contact the lower sides 10b
of the semiconductor bodies 10. In each case, the metallization
level 92 contacts the lower sides 10b of the semiconductor bodies
10. The metallization level 92 therefore constitutes a lower main
electrode for each of the semiconductor chips 1. It furthermore
fulfills the function of an adhesion promoter. It may be formed in
one or more layers; in the case of a multilayer structure, it may
also be formed as a sandwich. It may, for example, consist of
titanium or comprise one or more titanium layers. Optionally, the
metallization level 92 may also bear on the passivation layers 15
(if present) and/or on the embedding compound 4.
[0106] FIG. 65 shows by way of example the arrangement according to
FIG. 62 in an inverted position, and FIG. 66 shows an enlarged
detail of the arrangement, specifically after the optional form
milling of the arrangement in order to achieve a desired geometry.
The form milling may, as in all other configurations of the
invention, be carried out at any desired time after the pressing of
the semiconductor chip 1 into the embedding compound 4. The
enlarged detail according to FIG. 66 also shows a side edge 6r of
the residual assembly 6, as well as the optional connection piece
78 embedded in the embedding compound 4 in the vicinity of the side
edge 6r.
[0107] As furthermore represented in FIG. 69, a control electrode
interconnection structure 70 is applied onto the arrangement
according to FIG. 66, in such a way that the control electrodes 13
of the basic chip assemblies 2, and optionally the connection piece
78, are electrically conductively connected to one another by a
conductor structure 72 of the control electrode interconnection
structure 70, and therefore by the control electrode
interconnection structure 70.
[0108] The control electrode interconnection structure 70 may for
example again be formed as a prefabricated printed circuit board in
the form of a grid, or as a prefabricated electrically conductive
lead frame, placed on the residual assembly 6 and electrically
conductively connected to the control electrodes 13, and optionally
to the connection piece 78. The corresponding electrically
conductive connections may, for example, be established by means of
a solder or a layer with a sintered metal powder, or an
electrically conductive adhesive or by means of a pure pressure
contact connection. In the case of an electrically conductive lead
frame, the conductor structure 72 may for example be produced by
stamping a metal sheet.
[0109] Instead of applying the control electrode interconnection
structure 70 as a prefabricated unit onto the residual assembly 6,
the conductor structure 72 of the control electrode interconnection
structure 70 may also, as shown as a result in FIG. 67, be applied
onto the residual assembly 6 by a deposition method, and, as shown
as a result in FIG. 68, covered with a dielectric layer 73. The
dielectric layer 73 protects the conductor structure 73 and the
control electrodes 13 from contact with a starting material 31' for
the production of an upper connecting layer 31, which is
represented in FIG. 69 and, as shown as a result in FIG. 70, is
applied over the control electrode interconnection structure 70 and
its conductor structure 72, as well as over the control electrodes
13 and the upper main electrodes 11, onto the residual assembly 6.
Furthermore, application is furthermore carried out onto the one
starting material 32' for the production of a lower connecting
layer 32, over the lower main electrodes 12 and--if provided as in
the present example--over the metallization level 92. As may be
seen clearly in particular with the aid of the starting material
31' in FIG. 70, the starting material 31', but also the starting
material 32', may be used in order to compensate for irregularities
of the surface of the residual assembly 6.
[0110] As an alternative, however, it is likewise possible to apply
the starting material 31' in a structured way only above the upper
main electrodes 11, but not above the control electrodes 13 and not
above a conductor structure 72 of the control electrode
interconnection structure 70. In this case, the dielectric layer 73
may optionally be omitted.
[0111] The starting material 31' is used in order to produce an
upper connecting layer 31, which connects the upper main electrodes
11 with a material bonded connection and electrically conductively
to a common upper compensating plate 21. Correspondingly, the
starting material 32' is used in order to produce a lower
connecting layer 32, which connects the lower main electrodes 12
with a material bonded connection and electrically conductively to
a common lower compensating plate 22, as represented in FIG. 71 and
as a result in FIG. 72. FIG. 73 shows the entire arrangement of
FIG. 72.
[0112] The upper compensating plate 21 and the lower compensating
plate 22 are used for the same purpose and (apart from the large
extent perpendicular to the vertical direction v) may have the same
properties as, and may respectively be connected to the upper main
electrodes 11 and the lower main electrodes 12 in the same way as,
the upper compensating dies 21 and the lower compensating dies 22
according to the first exemplary embodiment. Accordingly, the upper
connecting layer 31 and the lower connecting layer 32 may have the
same structure, and be produced in the same way and from the same
starting materials 31' and 32', as the upper connecting layer 31
and the lower connecting layer 32, respectively, according to the
first exemplary embodiment.
[0113] As a result, for the residual assembly 6 provided with the
compensating plates 21, 22, in the same way as for the residual
assembly 6 of the first exemplary embodiment (FIG. 16) the
connection piece 78 covered by the embedding compound 4 or the
control electrode interconnection structure 70 covered by the
embedding compound 4, or its conductor structure 72, may be
electrically contacted by a connection electrode 75 and/or by a
control line 9, as already explained with the aid of the first
exemplary embodiment.
[0114] Furthermore, the residual assembly 6 may be arranged between
an electrically conductive upper contact plate 41 and an
electrically conductive lower contact plate 42, and optionally
inside a dielectric spacer ring 50, in such a way that the upper
contact plate 41 electrically and mechanically contacts the upper
compensating plate 21, and the lower contact plate 42 electrically
and mechanically contacts the lower compensating plate 22.
[0115] The upper contact piece 41 and the lower contact piece 42
may have the same properties, and consist of the same materials, as
the upper contact piece 41 and the lower contact piece 42 of the
first exemplary embodiment. FIG. 74 shows the finished
semiconductor arrangement 7, and FIG. 75 shows an exploded
representation thereof.
[0116] Although the upper contact piece 41 and/or the lower contact
piece 42 may optionally have an upper contact elevation 411 and a
lower contact elevation 421, as described above, for the contact
pieces 41 and 42 such contact elevations 411 and 421 may be omitted
since the contact pieces 41, 42 respectively do not need to contact
a plurality of separate compensating dies 21 or 22, but
respectively only one compensating die 21 or 22. For example, the
upper contact piece 41 and/or the lower contact piece 42 may
respectively be formed as a plane metal plate, which simplifies
production.
[0117] In order to achieve simultaneous switching on and off in the
case of semiconductor chips 1 which have identical switching
thresholds for switching on and off, provision may be made for the
resistances which the conductor structure 72 has between its
connection point 77 and the control electrode 13 of each of the
semiconductor chips 1 to be identical. In the case of a homogeneous
material or a homogeneous material structure of the conductor
structure 72, this can be achieved in all configurations and
exemplary embodiments of the invention most simply by the
conduction lengths which the conductor structure 72 respectively
has between its connection point 77 and the control electrodes 13
being of equal length. An example of this is shown in FIG. 78. The
connection point 77 is in this case given by the point of the
conductor structure 72 at which the conductor structure 72 is
connected to a connection piece 78 (if there is one), or to a
connection electrode 75 or a control line 9.
[0118] FIGS. 76, 77 and 79 show yet another alternative
configuration, according to which the control electrode
interconnection structure 70 may also have one or more passive
components 76, which are embedded in the embedding compound 4. The
passive component 76 may for example be resistors, but also any
other desired passive components, for example capacitors or
inductors. An example of one or more integrated gate resistors 76
is represented in FIGS. 76, 77 and 79. Such a gate resistor 76 may
respectively be connected in front of only one, or alternatively a
plurality or all of the control electrodes 13. Such a gate resistor
76 may, for example, have a resistance of at least 2 ohms.
[0119] As represented in FIG. 76, a passive component 76 may be
mounted on a conductor structure 72 of the control electrode
interconnection structure 70, for example in SMT technology
(Surface Mount Technology) or in thick-film technology. Likewise,
however, it is possible for a passive component 76 to constitute a
part of the conductor structure 72 of the control electrode
interconnection structure 70, as shown in FIGS. 77 and 79. The
examples shown each involve a resistor 76, which is formed by local
cross-sectional constriction of the conductor structure 72. The
resistors 76 are placed either before each semiconductor chip 1 or
before a multiplicity of semiconductor chips 1 connected in
parallel with one another. For example, the control electrodes 13
of two, three or four semiconductor chips 1 connected in parallel
may be connected via a common gate resistor 76 to the common
connection point 77.
[0120] With the aid of FIGS. 9 to 13, a method with which a
plurality of semiconductor chips 1 can be embedded in a common
embedding compound 4 was explained above. An alternative method to
this will now be explained with the aid of FIGS. 80 and 81.
[0121] First, as already described, an arrangement is produced in
which the semiconductor chips 1 are arranged next to one another on
a common carrier 300, as shown as a result by way of example in
FIG. 4. The die 310 is then placed above the semiconductor chips 1
in such a way that the semiconductor chips 1 are arranged between
mutually parallel surface sections of the carrier 300 and of the
die 310. Furthermore, a separating film 351 is placed between the
die 310 and the semiconductor chip 1. While preserving this
arrangement, the embedding compound 4 is then, as represented in
FIG. 80, injected between the separating film 351 and the carrier
300 by using an injection device 350, in such a way that at least
the intermediate spaces respectively lying between neighboring
semiconductor chips 1 are filled with the embedding compound 4. The
die 310 is protected from contact with the embedding compound 4 by
the separating film 351.
[0122] FIG. 81 shows the arrangement after the end of the injection
process and with the injection device 350 removed. After the curing
of the embedding compound 4, the die 310, the separating film 351
and the carrier 300 can then be removed from the assembly
comprising the semiconductor arrangements 2 and the cured embedding
compound 4.
[0123] With the aid of the examples explained so far, it has been
shown that a plurality or all of the semiconductor chips 1 of a
semiconductor arrangement 7 may be identical. It is, however, also
possible to use the present invention for a semiconductor
arrangement 7 of different and/or differently spatially oriented
semiconductor chips 1 and connect these with a material bonded
connection to one another by the embedding compound 4. As an
example, two different semiconductor chips 1, the semiconductor
bodies 10 of which have different thicknesses, may be mentioned.
The different thicknesses of the semiconductor chips 1 may
advantageously be compensated for by using differently thick upper
and/or lower compensating dies 21 and 22. One semiconductor chip 1
is for example a controllable semiconductor component, for example
a MOSFET or an IGBT, and the other semiconductor chip 1 is a diode.
In the finished semiconductor arrangement 7, comprising an upper
and a lower contact plate 41 and 42, the diode may for example be
formed as a freewheel diode which is electrically connected between
the upper main electrode 11 and the lower main electrode 12 of the
controllable semiconductor component. The residual assembly 6 of
the semiconductor arrangement 7 has an upper side 6t and a plane
lower side 6b parallel thereto.
[0124] Furthermore, the different thicknesses (in the vertical
direction v) of semiconductor bodies 10 of different semiconductor
chips 1 may also be compensated for by the upper connecting layer
31 and/or by the lower connecting layer 32, so that the residual
assembly 6 of the semiconductor arrangement 7 has mutually opposite
plane-parallel upper sides 6t and lower sides 6b.
[0125] In the exemplary embodiments explained so far, the upper
sides 6t and the lower sides 6b of the residual assembly 6 were
respectively plane-parallel. If these residual assemblies 6
respectively have mutually independent upper and/or lower
compensating dies 21 and 22, the associated upper contact plate 41
or lower contact plate 42 was provided with contact elevations 411
and 421, each of which was used for contacting a different upper or
lower compensating die 21 or 22.
[0126] It will now be explained below that, in the case of a
semiconductor arrangement 7 of which the residual assembly 6
mounted between the contact plates 41 and 42 has a plurality of
mutually independent upper compensating dies 21 and/or a plurality
of mutually independent lower compensating dies 22, the use of
simply configured upper and lower contact plates 41 and 42 can
nevertheless be achieved. Simply configured contact plates 41 and
42 are intended to mean contact plates which do not have contact
elevations 411 or 421, but have a structure which is simpler to
produce, for example respectively a plane surface section which
constitutes a plane electrical contact surface that contacts all
the upper or lower compensating dies 21 or 22.
[0127] The starting point is a semiconductor arrangement 7, the
residual assembly 6 of which has plane and mutually parallel upper
sides 6t and lower sides 6b. If this residual assembly 6 has a
plurality of mutually separated upper compensating dies 21, a part
of the upper side 6t is formed by the embedding compound 4. In
order to make these upper compensating dies 21 protrude out of the
embedding compound 4, so that they can be contacted by a plane
contact surface of an upper contact plate 41, the embedding
compound 4 may be lowered relative to the original upper side 6t of
the residual assembly 6.
[0128] The same applies correspondingly for the case in which the
residual assembly 6 of the semiconductor arrangement 7 has a
plurality of mutually separated lower compensating dies 22. Then,
specifically, a part of the lower side 6b is formed by the
embedding compound 4. In order to make these lower compensating
dies 22 protrude out of the embedding compound 4, so that they can
be contacted by a plane contact surface of a lower contact plate
42, the embedding compound 4 may be lowered relative to the
original lower side 6b of the residual assembly 6.
[0129] In principle, it is possible to lower the embedding compound
4 only on the upper side 6t or only on the lower side 6b of the
residual assembly 6, and only there to use an upper or lower
contact plate 41 or 42 having a plane contact surface with the
relevant compensating die 21 or 22, while the other, lower or upper
contact plate 41 or 42 is provided with contact elevations 421 or
411.
[0130] A semiconductor arrangement 7 according to the present
invention may then, as shown by way of example in FIG. 82, be
clamped between an electrically conductive upper pressure piece 81
and an electrically conductive lower pressure piece 82, in such a
way that there is respectively an electrical pressure contact
connection between the upper pressure piece 81 and the upper
contact plate 41, and between the lower pressure piece 82 and the
lower contact plate 42. The finished pressure contact arrangement 8
comprising the semiconductor arrangement 7, the upper pressure
piece 81 and the lower pressure piece 82, may then be electrically
interconnected. For example, the pressure contact arrangement 8 may
be connected in series with a resistive and/or inductive load 500
between a positive supply potential V+ and a negative supply
potential V-.
[0131] Furthermore, a plurality of, here merely by way of example
nine, separate residual assemblies 6 lying next to one another may
also be combined to form a larger unit 60, so that they can be
arranged between a common upper contact plate 41 and a lower
contact plate 42 and respectively electrically contacted by these
contact plates 41, 42.
[0132] Each of these residual assemblies 6 may for example comprise
four semiconductor chips 10 arranged in two rows and two columns,
nine semiconductor chips 10 arranged in three rows and three
columns, or, as shown, nine semiconductor chips arranged in three
rows and three columns.
[0133] In all configurations of the present invention, the control
electrode interconnection structure 70 may be embedded in the
embedding compound 4. In this case, the side of the control
electrode interconnection structure 70 facing away from the
semiconductor bodies 100 can be covered fully or at least partially
by a part of the embedding compound 4.
[0134] In principle, in a semiconductor arrangement in the sense of
the present invention, any desired number of mutually separated
semiconductor bodies 100 may be firmly connected to one another by
the embedding compound 4. The number may for example be at least 9,
at least 25 or at least 36.
[0135] It should be pointed out that the features and method steps
of the exemplary embodiments explained may be combined with one
another, unless otherwise mentioned.
* * * * *